Watchmaker&#39;s tool



Aug. 2, 1960 G. E. DYGERT 2,947,123

WATCHMAKER'S TOOL Filed April 24, 1959 I 2 Sheets-Sheet 1 INVENTOR, GEORGE E DVGERT ATTORwg Aug. 2, 1960 e. E. DYGERT 2,947,123

WATCHMAKERS TOOL Filed April 24. 1959 2 Sheets-Sheet 2 IN V EN TOR.

M WM ATTORNEYS United State Patent ,0

WATCHMAKERS TOOL George E. Dygert, 16956 E. Warren, Detroit, Mich.

Filed Apr. 24, 1959, Ser. No. 808,779

Claims. (Cl. 51259) This invention relates to a tool for use in removing shafts or studs which project from relatively small articles. An exemplary use of the tool is in removing staffs from the balance wheels of watches.

Balance wheels usually have relatively delicate construction. The staffs are usually made of a relatively hard metal such as hard steel. The staff usually has a thick hub portion which projects through and is secured within an opening in the center of the balance wheel by a rivet-like connection. "In watch repair it is frequently necessary to remove and replace a damaged stalf. It is practically impossible to drive the staff out of the balance wheel opening without distorting or otherwise damaging the relatively delicate balance wheel.

Heretofore, good watchmaking practice has required that the staif be mounted in a lathe and that the hub portion of the staff immediately adjacent the balance wheel face he cut off by a tool known in the trade as a lathe graver to remove a shoulder on the staff engaging the balance wheel face. The staff can then be driven out without damage to the balance wheel. This is a painstaking and relatively slowv process aggravated by the fact that the graver is small and delicate and must be frequently resharpened to cut the hard metal of the staff satisfactorily.

The object of the present invention is to provide a simple, relatively inexpensive structure facilitating rapid, convenient removal of a. staff from a balance wheel without damage to the balance Wheel.

The invention is carried out generally by providing agrinding wheel mountable in a jewelers lathe and a pivotally mounted holder arranged to support a balance wheel with its staff positioned to be ground off. by the grinding wheel. The pivotaLmount is arrangedto change the angular disposition of the staff so that it always projects generally radially towardthe grinding wheel even though the grind wheel diameter changes through wear or replacemengthereby insuring a substantially flat grind up to the face of the balance wheel. The balance Wheel holder is also provided with apunch and anvilwith which the ground-off staff may be driven out of the balance wheel. One form of the invention is shown in the accom panying drawings. I j @Fig. "1 is a side elevational view of a device made according tothis invention.- 7 V Fig. 2 is an end elevation thereof with the grind wheel 'axle'shown supported in a jewelers lathe chuck.

Fig. -3 is an enlarged sectional view on line 33 of Fig.2. L Fig. 4 is a fragmentary sectional view similarto Fig. 3 showing relation of the parts when a grind operation is complete. f 1 V V Fig. 5 is anenlarged, generally elevational viewshowinga balance wheel after the grinding operation posi-. tioned for operation thereon by a punch.

Fig.6 is a generally, sectional view on line 6-6 of Fig.3.

Fig. 7 is an enlarged top plan view of the balance wheel supporting arm separate from the other parts.

Fig. 8 is an enlarged, fragmentary sectional view illustrating parts in detail at the beginning of a grinding operation.

Fig. 9 is an enlarged, fragmentary elevational viewillustrating the parts when a grinding operation is complete.

Fig. 10 is an enlarged fragmentary sectional view illustrating the punch in position for operation.

Fig. 11 is a diagrammatic view illustrating different rotative positions of the balance wheel holding arm.

The device 20 of this invention includes a support 22 formed by side plates 24 and 26 secured at one end to an interposed spacer block 28 by such means as screws 30 and secured at their other ends to an interposed block 32 through a pivot 33. Block 32 forms one arm of an L- shaped balance wheel support 34. A grinding wheel 36 is secured on a shaft 38 between flange members 40, shaft 38 being journaled on plates 24 and 26 as illustrated in Fig. 6. Flanges 4t) and felt bushings 42 center grinding wheel 36 between the side plates. The grinding wheel shaft has a projecting end portion 44 adapted to be secured in the chuck 46 of a jewelers lathe represented in broken lines in Fig. 2. Block 28 has a lug 48 projecting beyond the side plates for engagement with a rest 50 on the jewelers lathe to secure holder 22 against rotation when the grinding wheel is turned.

The balance wheel holder 34 has an arm 52 projecting at right angles to arm 32 and the axis of pivot 33 for leg 32 is parallel to the axis of shaft 38 so that arm 52 extends over the top of wheel 36 generally in the plane of the wheel and can be swung in that plane toward and away from the wheel. Arm 52 has a generally flat top surface 54 for supportingly engaging a side face 55 of a a balance wheel 56 and the arm has a slot 58 through which the staff 60 of the balance wheel projects for engagement with grinding wheel 35. Slot 58 has a width at least as great as the width of grinding wheel 36 and is long enough to permit the grinding wheel to project through the entire thickness of arm 52 for a purpose to be described.

A leaf spring 62 is secured to balance wheel support 34 so that it projects adjacent the upper face 54 of arm 42. For this purpose arm 32 is shown as having an upwardly projecting portion 63 with threaded openings 64 (Fig. 7) and a slotted *upper face 65 to which one end of the spring is secured by such means as screws 66 (Fig. 3). A stud 70 is secured to leaf spring 62 by such means as a press fitted riveted sleeve 72 (Fig. 8). Stud 70 has a finger button 74 at itsupper end and its lower end is recessed at 76 to receive the upwardly projecting end 78 of the staff 60 of a balance wheel supported on arm 52. A sleeve of rubber or the like 80 is frictionally disposed around sleeve 72 and is yieldably pressed against the upper face of the balance wheel by leaf spring 62.

Arm 52 is provided with an anvil 82 having an upper surface 84 spaced above the top surface 54 of arm 52 for supportingly engaging a side face 86 of balance wheel 56 opposite from its side face 55 (Fig. 10). The anvil has a central opening 88 into which staff portion 78 projects.

Where arm 52 is made of a relatively soft material such as aluminum or-brass, anvil 82- preferably comprises a hollow stud 90 fitting in an opening 22 in arm 52 and having an outward upper flange seating on arm surface 54 and providing the anvil proper. The anvil is preferably made of a relatively hard metal, such as steel, and is secured in place by a set screw 94- threaded into a longitudinal opening in the free end of arm 52. Anvil 82 has a thickness suflicient to support the outer rim portion 96 of the balance wheel out of engagement with the top 54 of the arm. 7

A punch 98 is secured to spring 62 and has a head 100 for engagement by a mallet and has a point 102 centered with respect to anvil opening 88. Spring 62 biases punch 98 toward the anvil.

Referring to Fig. 8, the rim portion 96 of a balance wheel 56 is usually massive and carries balancing weights W. The portion of the balance wheel providing the side faces 55 and 86 is usually in the form of a relatively thin delicate spoke having a center aperture 104 through which the hub portion 106 of the balance wheel staff extends. Hub 106 has a portion 103 engaged within opening 104 with an adjacent shouldered portion 110 engaged against face 55 and another adjacent portion 112 upset outwardly into riveted relation with face 86.

In use, grinding Wheel shaft portion 44 is engaged with a jewelers lathe chuck 46 and lug 48 is engaged against rest 50 on the jewelers lathe as described. Leaf spring 62 is flexed upwardly away from arm 52 and a balance wheel is inserted beneath stud 64 and its rubber sleeve 80. Side face 55 of the balance wheel is seated on upper face 54 of arm 52 with its staff 60 projecting downwardly through slot 58. Spring 62 is then released and the spring presses sleeve 80 into clamping engagement against upper face 86 of the balance wheel, the upper portion '78 of the balance wheel staff projecting into stud recess '76. Arm 52 is lowered to a position wherein the end of the staff engages grinding wheel 36. This position of the parts is illustrated in Figs. 3 and 8.

The grinding Wheel 36 is rotated by the lathe and when light finger pressure is applied to button 74 balance wheel staff 60 is forced generally radially toward the grind wheel and is ground away. The grinding continues until the top surface 54 of arm 52 has moved downwardly to a position substantially tangent to the top of the grinding wheel at which time the statf has been ground off up to and including shoulder 110. This relation of the parts is illustrated in Figs. 4 and 9. During the grinding, the balance wheel is secured against rocking on arm 52 by sleeve 80 and is secured in its proper position circumferentially of the grinding wheel by engagement of recess 76 around upper staff end 78.

It is desirable to provide means for stopping downward rotation of arm 52 when the staff has been ground ofi to a condition in which it is in generally fiat continuation of balance wheel face 55 across opening 104 therein. For this purpose a stop screw 114 is threaded through an opening in block 28 so that its upper end 116 (Fig. 3) will engage the lower surface 118 of arm 52 at the proper rotative position thereof. A set screw 120 threaded into block 28 engages screw 14 for securing it in adjusted position.

When the staff has been ground off, spring 62 is again flexed upwardly and the balance wheel is removed, inverted, and placed on anvil 82 with its remaining staff projection 78 extending into recess 88. Spring 62 is then released and punch point 102 is urged by the spring against the ground off face 122 of the staff (Figs. 5 and Asshown in Fig. 5, the punch point 102 is long enough to insure its engagement against staff face 122 while the clamping stud 70 is still spaced slightly above top surface 54 of arm 52. Opening 88 is relatively small so that it supports the central portion of the balance wheel inwardly to a point immediately adjacent its central opening 104. Punch head 100 may then be struck lightly with a mallet M to drive the staff out of opening 104 into recess 88. Spring 62 is then flexed upwardly and the balance wheel removed.

During the course of a number of grinding operations, grinding wheel 36 will wear away so that its diameter will change materially. It is desirable to provide means for insuring that the balance wheel staff 60 will always be disposed in a direction substantially radial of the grinding wheel despite these variations in the grinding, wheel diameter. Structure for accomplishing this is illustrated in Fig. 11. The axis of pivot 33 and grinding wheel shaft 38 lie in a common plane P. Arm 52 is spaced above pivot axis 33 and is arranged so that when a wheel 36b of an intermediate size is in use and the top of the grinding wheel is tangent to upper arm surfaces 54, arm 52 projects generally parallel to plane P as represented at 52b. The point of tangency is represented at Tb and in this position the balance wheel staff will project along line b generally perpendicular to plane P. Thus a flat grind may be obtained.

When the grinding wheel wears down to a size representcd at 360, the point of tangency will shift circumferentially of the grinding'wheel to a position represented at Tc and the staff will project along a line c. Line 0 is tilted with respect to line b because of the rotation of arm 52 about pivot 33 to a lower position 520. The angle of tilt is such that line 0 extends substantially along a radius of the grinding wheel. Thus a substantially fiat grind is obtained at this point also.

Eventually the grinding Wheel may be replaced with a new one having a diameter represented at 36a. The point of tangency between its upper edge and surface 54 of arm 52 will be circumferentially shifted to the right of tangent Tb as represented at Ta. This results from a lesser downward swing of the arm to the position indicated at 52a when the larger Wheel is used. Here again the direction of extent of the balance wheel staff is tilted commensurately to the circumferential shift of the tangent point and the line a, along which the staff will project, is again substantially radial of the grinding wheel so that the flat grind is obtained.

It will be appreciated that lines a and c may not extend precisely coincidentally with radii of the grinding wheel. However, as a practical matter, within the range of diameters of grinding wheels in use a satisfactorily flat grind across the hub portion of the stalf will be obtained to facilitate punching the remaining portion of the staff out of opening 104 without significant damage to the balance wheel.

From time to time as a grinding wheel wears down or where a grinding wheel is replaced with a new one, screw 116 will be turned in block 28 to adjust the stop location for downward movement of arm 52. This is done by first backing off screw 120, then turning screw 116 to obtain the desired adjustment and then retightening screw 120 to secure screw 116 in position. It may also be desirable from time to time to replace anvil element 82 should it become worn. This is done by simply retracting set screw 94, lifting the anvil out of recess 92, inserting a new anvil and securing it in place by advancing screw 94.

I claim:

1. A watchmakers tool for removing the staffs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, a holder adapted to hold a balance wheel with a portion of its staff disposed toward said grinding wheel, said holder being mounted for movement on said support toward said grinding wheel for advancing the staff into grinding engagement against said grinding Wheel, means forming a balance wheel supporting anvil on said tool, said tool having an opening adjacent said anvil to receive another portion of a balance wheel staff supported on said anvil, and means forming a punch mounted on said holder for aligned movement toward said opening for driving a portion of the staff loose from the balance wheel into said opening.

2. A watchmakers tool for removing the staffs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, a balance wheel holder including an element adapted to support a side face of a balance wheel and having an opening through which an end of the balance wheel stalf projects toward said grinding wheel, said holder also including a spring pressed clamping element engageable against the other side face of the balance wheel, said holder being mounted for movement on said support toward said grinding wheel for advancing the end portion of the staff into g'rinding engage- ,to' hold said punch against a portion of the balance wheel staff and in alignment with said recess, said punch being movable toward said recess for driving the portion of the stafi remaining after the grinding operation loose from the balance wheel to said recess.

3. A watchmakers tool for removing the stafls from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, a balance wheel holder including an element adapted to support aside face of a balance wheel and having an opening through which an end of the balance wheel stafi projects toward said grinding wheel, a leaf spring mounted on said holder flexible away from said element to facilitate mounting a balance wheel on said element for grinding, a clamping member yieldably pressed by said spring against the other face of the "balance wheel for holding it in grinding position,said holder being mounted'for movement on said support toward said grinding wheel for advancing the endportion of the staif into grinding engagement against said grinding wheel, means forming a balance wheel supporting anvil on said holder recessed to receive another end of a balance wheel staff, means forming a punch mounted on said spring andyieldably urged in aligned relationtoward said recess, whereby to facilitate driving the portion of the staff remaining after the grinding'operationloose from the balance wheel to said recess. '4. A watchmakers tool for removing the staffs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, a balance wheel holder including an element adapted to support a side face of a balance wheel and having an opening through which an end of the balance wheel staff projects toward said grinding wheel, a leaf spring mounted on said holder and projecting adjacent said element, a clamp secured on said spring and being urged toward said element in alignment with said opening therein for engaging against the other side face of a balance wheel and holding the same on said element for grinding, said clamp .having a recess aligned with said opening in said element for receiving and positioning the other end of the balance wheel staff, means forming on said holder and anvil adapted to support a side face of a balance wheel and being recessed to receive the other end of a balance wheel staif, means forming a punch mounted on said leaf spring and urged thereby in aligned relation toward said recess for engaging the portion of the staff remaining after the grinding operation, whereby to facilitate driving said staff loose from the balance wheel into said recess, said leaf spring being yieldably flexible away from said holder element to facilitate mounting a balance wheel selectively in grinding position and punching position on said element.

5. A watchmakers tool for removing the staffs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, a holder adapted to supportingly engage one side face of a balance wheel and having an open portion through which one end of the balance wheel staff projects toward engagement with said grinding wheel, said holder being mounted for movement on said support toward said grinding wheel for advancing the staff into grinding engagement against said grinding wheel, said opening portion having a width at least as great as the width of the grinding wheel and having a length dimensioned so that said grinding wheel may project through said holder for grinding the staff off up to the side face'of the balance wheel supported by said holder, means forming a balance wheel supporting anvil on said holder adapted to supportingly engage a side face of a balance wheel, said holder having a recess adjacent said anvil into which another portion of the balance wheel 6 on said holder for aligned movement toward said recess for driving a portion of the staff loose from the balance wheel into said recess.'

6. A watchmakers tool for removing the stafis fromv balance wheels or the like comprising, a support with a grinding wheel having an axle journaled on said support, said a'xle having a projecting portion adapted to be enga'ged within the chuck of a jewelers lathe, means on said support adapted to engage a stationary rest to secure said support against rotation, a holderadapted to hold a balance wheel witha portion of its staff disposed toward saidgrinding wheel, said holder being mounted for movement on said support toward said grinding wheel vfor advancing the stalf intogrinding engagement against said grindingwhe'el', a balance wheel supporting anvil on said holder recessed to receive another portion of a balance wheel stafi, and means forming a punch mounted on said holder for aligned movement toward said recess for driving a portion of the staff loose from the balance wheel into said recess. a

7; A watchmakers tool for removing the stafis from balance wheels or the like comprising, a'support with a grinding wheel journaled thereon, a balance wheel holder pivotally mounted on said support for movement toward and away from said grinding wheel, said holder being adapted to supportingly engage a side face of a balance wheel 'and'having an opening through which the balance wheel staff projects toward said grinding wheel for grinding engagement therewith, said opening having a width at least as great as the width of said grinding wheel, said opening havinga length dimensioned so that said grinding wheel may pass through said portion of said holder, whereby to facilitate grinding off said portion of the balance wheel staif substantially flatly up to the side face of the balance wheel supported by said holder, a stop mounted on said support at a location displaced from the pivotal mount of said holder, said stop being positioned to engage said holder and limit movement thereof toward said grinding wheel, said stop being adjustably movable in a direction transverse to the grinding wheel axis and stopping wheelward movement of said holder when the surface of said grinding wheel has passed through said opening and is substantially tangent to the portion of said holder supporting the balance wheel.

8. A watchmakers tool for removing the staifs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, a balance wheel holder pivotally mounted on said support, said holder including means adapted to secure a balance wheel at a location thereon wherein its staff extends in a direction substantially radial ofsaid grinding wheel in one rotative position of said holder and projects into grinding engagement with said grinding wheel, the pivotal mount for said holder being displaced from the axis of rotation of said grinding wheel in a plane, said plane passing through said axis and extending substantially perpendicular to said direction, said balance wheel securing means on said holder shifting circumferentially of said grinding wheel responsive to changes of rotative position of said holder, the angle of disposition of said means and of a balance wheel staff projecting therefrom shifting toward alignment with grinding wheel radii passing through the shifted circumferential positions, whereby when the grinding wheel diameter decreases incident to wear or increases upon replacement thereof, the angular attitude of a balance wheel stafl remains generally radial of said grinding wheel.

9. A watchmakers tool for removing the staffs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, an L shaped member having one arm pivotally mounted on said support with the other arm projecting adjacent said grinding wheel in the general plane thereof, the axis of the pivotal mount of said one arm being generally parallel to the axis of said grinding wheel so that said other arm moves toward and away from said grinding wheel in the general plane thereof, said other arm including means adapted to secure a balance wheel at a location thereon, wherein its staff extends in a direction substantially radial of said grinding wheel in one rotative position of said holder and projects into grinding engagement with said grinding wheel, said pivotal mount being displaced from the axis of rotation of said grinding wheel in a plane, said plane passing through said grinding wheel axis and extending substantially perpendicularly to said direction, said balance wheel securing means shifting circumferentially of said grinding wheel responsive to changes of rotative position of said member, the angular disposition of said means and of a balance wheel staff projecting therefrom shifting toward alignment with grinding wheel radii passing through the shifted circumferential positions, whereby when the grinding wheel diameter decreases incident to wear or increases upon replacement thereof, the angular attitude of a balance wheel staff remains generally radial of said grinding wheel.

10. A watchmakers tool for removing the staffs from balance wheels or the like comprising, a support with a grinding wheel journaled thereon, an L shaped holder having a relatively short arm pivotally mounted on said support on an axis substantially parallel to the axis of said grinding Wheel, said holder having a relatively long arm projecting over the top of said grinding wheel and being swingable toward and away from said grinding wheel generally in the plane thereof, said long arm having a substantially flat top surface portion for supportingly engaging a side face of a balance wheel, said flat surface 'portion having a slot through which an end of a balance wheel staff may project toward said grinding wheel,

said slot having a width at least as great as the width of said grinding wheel and having a length dimension great enough to enable said long arm to be swung downwardly 'until its said flat surface portion is substantially tangent to the top of the grinding wheel, a leaf spring secured -on said holder and projecting in spaced relation above above the top of said long arm a distance at least as great as the thickness of a balance wheel, whereby to supportingly engage a side face of a balance wheel with the rim of the balance wheel substantially unsupported, said anvil having a central opening into which a portion of a balance wheel staff may project, means forming a punch supported by said leaf spring in alignment with said anvil opening to facilitate driving a ground 01f portion of a balance wheel staff loose from the balance Wheel and into said opening, said leaf spring having a free end manually engageable for flexing said leaf spring upwardly away from said arm to facilitate mounting a balance Wheel selectively on said fiat surface portions for grinding and punching, a stop secured on said suport and engageable with an under surface portion of said long arm for limiting downward movement of said long arm when its said flat surface portion is substantially tangent to the top of said grinding wheel, said stop being threadedly mounted for vertical movement relative to said grinding wheel for adjusting the stop position of said long arm.

No references cited. 

